Model of Memory
RETRIEVAL
Turning now to Long-Term Memory
ATTENTION
Sensory
Signals
Sensory
Memory
Short-Term
Memory
Long-Term
Memory
REHEARSAL
Long-Term Memory
• Characteristics (intuitive with some
introspection):
– Persists indefinitely (up to decades!)
– Requires no active process of rehearsal (at
least that we are conscious of)
Long-Term Memory
• Characteristics (intuitive with some
introspection):
– Persists indefinitely (up to decades!)
– Requires no active process of rehearsal (at
least that we are conscious of)
– What are some examples of Long-Term
Memories?
Some Distinctions in LTM
• Endel Tulving: There are two broad
categories of information that are
represented in LTM • Examples:
– What did you eat for breakfast?
– What is the capital of Canada
– Where were you when…
– Are maple trees deciduous?
– Riding a bike !?
Some Distinctions in LTM
• Endel Tulving: There are two broad
categories of information that are
represented in LTM • Episodic Memory: memory of an event
in your life
• autobiographical
• has a temporal context - something about time
is encoded along with the memory
Some Distinctions in LTM
• Endel Tulving: There are two broad
categories of information that are
represented in LTM • Semantic Memory: memory of facts,
knowledge of the world
• unconnected to an autobiographical event
• no temporal context
Some Distinctions in LTM
• A third category may be distinguished:
– Example: riding a bike, playing an
instrument
Some Distinctions in LTM
• Procedural Memory: memory for actions
Semantic Memory
• Capacity is huge (unlimited?)
Semantic Memory
• Structure of encoding is associative
Semantic Memory
• Structure of encoding is associative
– Evidence: Semantic Priming in a LexicalDecision Task
• Priming: prior exposure to some stimulus
modifies subsequent processing of a target
Semantic Memory
• Structure of encoding is associative
– Evidence: Semantic Priming in a LexicalDecision Task
• Lexical Decision Task: Subject is shown a
target word or pronounceable non-word (eg.
gap or fap) and must respond “word” or “nonword”
Semantic Memory
• Structure of encoding is associative
– Evidence: Semantic Priming in a LexicalDecision Task
• manipulation: prime can be either related or
unrelated to the target word
Semantic Memory
• Structure of encoding is associative
– Evidence: Semantic Priming in a LexicalDecision Task
• result: words are identified faster when
preceded by a semantically related prime
Prime
“space”
“truck”
Target
“gap”
“gap”
Response
fast
slow
Semantic Memory
• Structure of encoding is associative
– Evidence: Semantic Priming in a LexicalDecision Task
– Interpretation:
• the representation of information in semantic
memory is associative:
• each fact or piece of knowledge is stored along
with its relationship to other stored information
• related items can activate each other which
facilitates recall
Semantic Memory
• Structure of encoding is associative
– Example: Accessing a memory that is “on
the tip of your tongue”
• you’re trying to rent a movie but you can’t recall
the title of the one you have in mind, you scan
through the associated facts: the actors, the
plot, the setting, etc. until the title surfaces
• each recalled piece of knowledge “activates”
related knowledge until the title is sufficiently
activated
Semantic Memory
• Structure of encoding is associative
– This idea is formalized in so-called
“connectionist” networks
skiing
highschool
mockingbird
bird
canary
chicken
Mr. Lacey
To Kill A Mockingbird
racism
English
Martin Luther King
Episodic Memory
• Memory for an episode or event in your
own life
Episodic Memory
• Memory for an episode or event in your
own life
• Has temporal context (entails a sense of
duration and date)
Episodic Memory
• Memory for an episode or event in your
own life
• Has temporal context (entails a sense of
duration and date)
• examples:
– recall breakfast
– what happened this weekend
Recalling Episodic Memory
• Recall is highly sensitive to context Similarities in context (especially smell)
can trigger vivid recollections
Recalling Episodic Memory
• Memory is affected by the nature of
your engagement with the information
• Levels-of-Processing Theory
Recalling Episodic Memory
• Memory is affected by the nature of
your engagement with the information
• Levels-of-Processing Theory
– Consider this experiment:
List
CAT
pie
PILLOW
TREE
Method of Learning
• stating capitals or lower-case
•repeating words
• putting words into a sentence
Recall is tested some time later.
Recalling Episodic Memory
• Memory is affected by the nature of
your engagement with the information
• Levels-of-Processing Theory
– Consider this experiment:
List
CAT
pie
PILLOW
TREE
Result:
•Best recall with “deep”
processing
•Worst recall with “surface”
processing
Recalling Episodic Memory
• Memory is affected by the nature of
your engagement with the information
• Interpretation:
– the successful use of memory depends on
the number of connections that are made
between related items and the degree to
which these are initially activated
Recalling Episodic Memory
• context is critical!
– location, physiological state, etc. affect
ability to recall
– e.g. lists of words are recalled better when
recalled where they were first learned
When You Don’t Remember
• Two reasons why you don’t remember:
When You Don’t Remember
• Two reasons why you don’t remember:
• Unavailable
– It wasn’t successfully encoded - something
went wrong while you were studying
When You Don’t Remember
• Two reasons why you don’t remember:
• Unavailable
– It wasn’t successfully encoded - something
went wrong while you were studying
• Inaccessible
– memory is stored but cannot be retrieved,
perhaps because appropriate connections
aren’t being made
Recalling Episodic Memory
• Recall is a generative processes rather
than simply calling up stored data
Recalling Episodic Memory
• Recall is a generative processes rather
than simply calling up stored data
• Evidenced by the fact that episodic
memories can be distorted or
completely false under certain
circumstances